One of the central characteristics of disciplines is that they create their own particular ways of knowing the world. This process is facilitated by the specialization and refinement of disciplinary-specific semiotic resources over time. Nowhere is this truer than in the sciences, where it is the norm that disciplinary-specific representations have been introduced and then refined by a number of different actors. As a consequence, many of the semiotic resources used in the sciences today still retain some traces of their historical roots.

In this paper we analyse one such disciplinary-specific semiotic resource from the field of Astronomy—the Hertzsprung-Russell diagram. We audit the potential of this semiotic resource to provide access to disciplinary knowledge—what Fredlund et al (2012) have termed its disciplinary affordances. Our analysis includes consideration of the use of scales, labels, symbols, sizes and colour. We show how, for historical reasons, the use of these aspects in the resource may differ from what might be expected by a newcomer to the discipline.

We suggest that some of the issues we highlight in our analysis may, in fact, be contributors to alternative conceptions and therefore propose that lecturers pay particular attention to the disambiguation of these features for their students.

Becoming part of a discipline involves learning to interpret and use a range of disciplinary-specific semiotic resources (Airey, 2009). These resources have been developed and assigned particular specialist meanings over time. Nowhere is this truer than in the sciences, where it is the norm that disciplinary-specific representations have been introduced and then refined by a number of different actors in order to reconcile them with subsequent empirical and theoretical advances. As a consequence, many of the semiotic resources used in the sciences today still retain some (potentially confusing) traces of their historical roots. However, it has been repeatedly shown that university lecturers underestimate the challenges such disciplinary specific semiotic resources may present to undergraduates (Northedge, 2002; Tobias, 1986).

In this paper we analyse one such disciplinary-specific semiotic resource from the field of Astronomy—the Hertzsprung-Russell diagram. First, we audit the potential of this semiotic resource to provide access to disciplinary knowledge—what Fredlund et al (2012)have termed its disciplinary affordances. Our analysis includes consideration of the use of scales, labels, symbols, sizes and colour. We show how, for historical reasons, the use of these aspects in the resource may differ from what might be expected by a newcomer to the discipline. Using the results of our analysis we then created an online questionnaire to probe what is discerned (Eriksson, Linder, Airey, & Redfors, in press) with respect to each of these aspects by astronomers and physicists ranging from first year undergraduates to university professors.

Our findings suggest that some of the issues we highlight in our analysis may, in fact, be contributors to the alternative conceptions of undergraduate students and we therefore propose that lecturers pay particular attention to the disambiguation of these features for their students.

In the late 70’s Gibson (1979) introduced the concept of affordance. Initially framed around the needs of an organism in its environment, over the years the term has been appropriated and debated at length by a number of researchers in various fields. Most famous, perhaps is the disagreement between Gibson and Norman (1988) about whether affordances are inherent properties of objects or are only present when they are perceived by an organism. More recently, affordance has been drawn on in the educational arena, particularly with respect to multimodality (see Linder (2013) for a recent example). Here, Kress et al. (2001) have claimed that different modes have different specialized affordances. Then, building on this idea, Airey and Linder (2009) suggested that there is a critical constellation of modes that students need to achieve fluency in before they can experience a concept in an appropriate disciplinary manner. Later, Airey (2009) nuanced this claim, shifting the focus from the modes themselves to a critical constellation of semiotic resources, thus acknowledging that different semiotic resources within a mode often have different affordances (e.g. two or more diagrams may form the critical constellation).

In this theoretical paper the concept of disciplinary affordance (Fredlund et al., 2012) is suggested as a useful analytical tool for use in education. The concept makes a radical break with the views of both Gibson and Norman in that rather than focusing on the discernment of one individual, it refers to the disciplinary community as a whole. Put simply, the disciplinary affordances of a given semiotic resource are determined by those functions that the resource is expected to fulfil by the disciplinary community. Disciplinary affordances have thus been negotiated and developed within the discipline over time. As such, the question of whether these affordances are inherent or discerned becomes moot. Rather, from an educational perspective the issue is whether the meaning that a semiotic resource affords to an individual matches the disciplinary affordance assigned by the community. The power of the term for educational work is that learning can now be framed as coming to discern the disciplinary affordances of semiotic resources.

In this paper we will briefly discuss the history of the term affordance, define the term disciplinary affordance and illustrate its usefulness in a number of educational settings.

Learning physics can be compared to learning a new language in several respects. This includes learning to “read and write” the representations that carry the meaning of the language. In the case of physics these representations include text, gestures, mathematics, graphs, images, simulations and animations. For those who are fluent in the language, these representations are full of meaning but for the novice learning to discern the relevant disciplinary aspects of these representations (disciplinary discernment) can be a struggle. Research has shown that often teachers assume that students “see” the same things in a representation that they do. However, this is usually not true. Learning to discern disciplinary aspects of representations is something that students need help with (scaffolding). One important aspect of learning representational fluency in physics is that of spatial thinking, in particular learning to extrapolate three-dimensionality from one- and two-dimensional representations.

In this talk I will present a theoretical framework describing the process of teaching and learning representational disciplinary fluency. I will also provide some examples to illustrate the framework, from the perspectives of the instructor and the student.

This theoretical paper introduces a new way to view and characterize teaching and learning astronomy. It describes a framework, based on results from empirical data, analyzed through standard qualitative research methodology, in which a theoretical model for vital competencies of learning astronomy is proposed: Reading the Sky . This model takes into account not only disciplinary knowledge but also disciplinary discernment and extrapolating three-dimensionality . Together, these constitute the foundation for the competency referred to as Reading the Sky . In this paper, I describe these concepts and how I see them being connected and intertwined to form a new competency model for learning astronomy and how this can be used to inform astronomy education to better match the challenges students face when entering the discipline of astronomy: The Spiral of Teaching and Learning . Two examples are presented to highlight how this model can be used in teaching situations.

Teaching and learning astronomy is known to be both exciting and challenging. To learn astronomy demands not only disciplinary knowledge, but also the ability to discern meaning from disciplinary specific representations (disciplinary discernment). This includes the ability to think spatially, in particular, extrapolating three-dimensionality from a one- or two-dimensional input i.e. to be able to visualize in one’s mind how a three-dimensional astronomical object may look from a one- or two-dimensional input such as from a visual image or a mathematical representation. In this talk I demonstrate that these abilities are deeply intertwined, and that to learn astronomy at any level demands becoming fluent in all three aspects (disciplinary knowledge, disciplinary discernment and spatial thinking). A framework is presented for how these competencies can be described, and combined, as a new and innovative way to frame teaching and learning in astronomy. It is argued that using this framework “Reading the Sky” optimizes the learning outcomes for students. The talk also suggests strategies for how to implement this approach for improving astronomy teaching and learning overall.

Teaching and learning astronomy is known to be both exciting and challenging. To learn astronomy demands not only disciplinary knowledge, but also ability to discern affordances from disciplinary specific representations used within the discourse, which we call disciplinary discernment, and ability to think spatially, which we refer to as extrapolating three-dimensionality from a two dimensional input. Disciplinary knowledge involves all the knowledge that constitutes the discipline, disciplinary discernment involves discernment of the affordances of disciplinaryspecific representations, and extrapolating three-dimensionality involves the ability to visualize in ones mind how a three-dimensional astronomical object may look from a two-dimensional input (image or simulation). In this paper we argue that these abilities are intertwined and to learn astronomy at any level demands becoming fluent in all three. A framework is presented for how these abilities can be described and combined as a new and innovative way to frame teaching and learning in astronomy for optimizing the learning outcome of students - what we refer to as developing the ability to Read the Sky. We conclude that this is a vital competency needed for learning astronomy and suggest strategies for how to implement this to improve astronomy education.

Teaching and learning astronomy is known to be both exciting and challenging. However, learning astronomy at university level is a demanding task for many students. The learning pro-cess involves not only disciplinary knowledge, but also the ability to discern affordances from disciplinary specific representations used within the astronomy discourse, which we call discipli-nary discernment (Eriksson, Linder, Airey, & Redfors, 2014a) and ability to think spatially, which we refer to as extrapolating three-dimensionality from a two dimensional input (Eriksson, Linder, Airey, & Redfors, 2014b). Disciplinary knowledge involves all the knowledge that con-stitutes the discipline, disciplinary discernment involves discernment of the affordances of disci-plinary-specific representations, and extrapolating three-dimensionality involves the ability to visualize in ones mind how a three-dimensional astronomical object may look from a two-dimensional input (image or simulation). In this paper we argue that these abilities are inter-twined and to learn astronomy at any level demands becoming fluent in all three abilities. A framework is presented for how these abilities can be described and combined as a new and in-novative way to frame teaching and learning in astronomy at university level for optimizing the learning outcome of students - what we refer to as developing the ability of Reading the Sky (Eriksson, 2014). We conclude that this is a vital competency needed for learning astronomy and suggest strategies for how to implement this to improve astronomy education.

This talk concerns astronomy eduction resercher and focus on what visualizations offer for learning astronomy at all levels. I will be presenting reserach results concerning disciplinary discernment and spatial thinking in relation to experiences offered by planetarium presentations.

Teaching and learning astronomy is known to be both exciting and challenging. To learn astronomy demands not only disciplinary knowledge, but also ability to discern affordances from disciplinary specific representations used within the discourse, which we call disciplinary dis- cernment (Eriksson, Linder, Airey, & Redfors, 2014a) and ability to think spatially, which we refer to as extrapolating three-dimensionality from a two dimensional input (Eriksson, Linder, Airey, & Redfors, 2014b). Disciplinary knowledge involves all the knowledge that constitutes the discipline, disciplinary discernment involves discernment of the affordances of disciplinary- specific representations, and extrapolating three-dimensionality involves the ability to visualize in ones mind how a three-dimensional astronomical object may look from a two-dimensional input (image or simulation). In this paper we argue that these abilities are intertwined and to learn as- tronomy at any level demands becoming fluent in all three abilities. A framework is presented for how these abilities can be described and combined as a new and innovative way to frame teach- ing and learning in astronomy at university level for optimizing the learning outcome of students - what we refer to as developing the ability of Reading the Sky (Eriksson, 2014). We conclude that this is a vital competency needed for learning astronomy and suggest strategies for how to implement this to improve astronomy education.

When students start to learn physics and astronomy, they immediately are confronted with a multitude of representations packed with disciplinary information. This information is embedded in these representations and the students need to learn to discern the relevant information. This is not straightforward, and requires a lot of teaching and practice before being mastered. It carries many similarities to learning a new language – the language of physics, astronomy, or other sciences.

However, it all starts with disciplinary discernment from those representations, something that has been shown to be challenging for students. Often the teacher who knows the representations and their appresented meaning—their disciplinary affordances—assumes that the students discern the same things in those representations as the teacher does. Research has shown that this is not the case and such assumptions leads to educational problems for the students and make learning physics or astronomy unnecessary difficult, or even inaccessible to the students. The students need be given the opportunity to develop their competency in discerning disciplinary-specific relevant aspects from representations; a competency referred to as Reading the Sky in an astronomy context, and described by the Anatomy of Disciplinary Discernment (Eriksson, 2014a; Eriksson et al., 2014b).

Furthermore, physics and astronomy are subjects aiming to describe the real multidimensional world, hence involve a substantial amount of spatial thinking. The students need to learn to extrapolate three-dimensionality in their minds from two-dimensional representations, which have been shown to be challenging to students. Unfortunately, this competency is often taken for granted and rarely addressed in teaching (Eriksson et al., 2014c).

In this talk we present a model in which we identify and describe the critical competencies needed to “read” disciplinary-specific representations; it concerns not only disciplinary discernment but also spatial thinking and disciplinary knowledge. These are combined into the Spiral of Teaching and Learning (STL), a new and powerful model for optimizing teaching and learning science (Eriksson, 2014a; Eriksson, 2015). We discuss consequences and possibilities when applying the STL model and give an example of how this model can be used in teaching and learning astronomy.

Aims. To investigate the astrometric effects of stellar surface structures as a practical limitation to ultra-high-precision astrometry (e.g. in the context of exoplanet searches) and to quantify the expected effects in different regions of the HR-diagram. Methods. Stellar surface structures (spots, plages, granulation, non-radial oscillations) are likely to produce fluctuations in the integrated flux and radial velocity of the star, as well as a variation of the observed photocentre, i.e. astrometric jitter. We use theoretical considerations supported by Monte Carlo simulations (using a starspot model) to derive statistical relations between the corresponding astrometric, photometric, and radial velocity effects. Based on these relations, the more easily observed photometric and radial velocity variations can be used to predict the expected size of the astrometric jitter. Also the third moment of the brightness distribution, interferometrically observable as closure phase, contains information about the astrometric jitter. Results. For most stellar types the astrometric jitter due to stellar surface structures is expected to be of the order of 10 micro-AU or greater. This is more than the astrometric displacement typically caused by an Earth-size exoplanet in the habitable zone, which is about 1-4 micro-AU for long-lived main-sequence stars. Only for stars with extremely low photometric variability (< 0.5 mmag) and low magnetic activity, comparable to that of the Sun, will the astrometric jitter be of the order of 1 micro-AU, sufficient to allow the astrometric detection of an Earth-sized planet in the habitable zone. While stellar surface structure may thus seriously impair the astrometric detection of small exoplanets, it has in general a negligible impact on the detection of large (Jupiter-size) planets and on the determination of stellar parallax and proper motion. From the starspot model we also conclude that the commonly used spot filling factor is not the most relevant parameter for quantifying the spottiness in terms of the resulting astrometric, photometric and radial velocity variations.

Traditionally, astronomy and physics have been viewed as difficult subjects to master. The movement from everyday conceptions of the world around us to a disciplinary interpretation is fraught with pitfalls and problems. What characterises a disciplinary insider’s discernment of phenomena in astronomy and how does it compare to the views of newcomers to the field? In this paper we report on a study into what students and professors discern (cf. Eriksson et al, in press) from the same disciplinary semiotic resource and use this to propose an Anatomy of Disciplinary Discernment (ADD) as an overarching characterization of disciplinary learning.

Students and professors in astronomy and physics were asked to describe what they could discern from a simulation video of travel through our Galaxy and beyond (Tully, 2012). In all, 137 people from nine countries participated. The descriptions were analysed using a hermeneutic, constant comparison approach (Seebohm, 2004; Strauss, 1987). Analysis culminated in the formulation of five hierarchically arranged, qualitatively different categories of discernment. This ADD modelling of the data consists of one non-disciplinary category and four levels of disciplinary discernment: Identification, Explanation, Appreciation, and Evaluation. Our analysis demonstrates a clear relationship between educational level and the level of disciplinary discernment.

The analytic outcomes of the study suggest that teachers may create more effective learning environments by explicitly crafting their teaching to support the discernment of various aspects of disciplinary semiotic resources in order to facilitate the crossing of boundaries in the ADD model.

Learning astronomy has many learning challenges due to the highly diverse, conceptual, and theoretical thinking used in the discipline. One taken for granted challenge is the learning to

extrapolate three-dimensionality. Although we have the ability to see our surroundings in three- dimensional terms, beyond a distance of about 200m this ability quickly becomes very limited. So, when looking up at the night sky, learning to discern critical features that are embedded in dimensionality does not come easily. There have been several articles addressing how fruitful 3D simulations are for astronomy education, but they do not address what students discern, nor the nature of that discernment. Taking the concept of discernment to be about noticing something and assigning meaning to it, our research question is: In terms of dimensionality, what do astronomy/physics students and professors discern when engaging with a simulated video fly- through of our Galaxy and beyond?

A web-based questionnaire was designed using links to video clips drawn from a well-regarded simulation-video of travel through our galaxy and beyond. 137 physics and astronomy university students and teaching professors, who were drawn from nine countries, completed the questionnaire. The descriptions provided by them were used to formulate six categories of discernment in relation to multidimensionality. These results are used to make the case that astronomy learning that aims at developing the ability to extrapolate three-dimensionality needs to be grounded in the creation of meaningful motion parallax experiences. Teaching and learning implications are discussed.

This paper aim at investigating what astronomy students and experts discern from the multitude of different disciplinary affordances available in Hertzsprung-Russell (HR) diagrams. HR-diagrams are central to all of astronomy and astrophysics and used extensively in teaching. However, knowledge about what students and experts discern from these disciplinary representations are not well known at present. HR-diagrams include many disciplinary affordances that may be hidden to the novice student, hence we aim at investigating and describing what astronomy students at different university levels (introductory, undergraduate, graduate), and astronomy educators/professors, discern from such representation – referred to as disciplinary discernment (Eriksson, Linder, Airey, & Redfors, 2014). Data from a web based questionnaire were analysed using the Anatomy of Disciplinary Discernment (ADD) framework by Eriksson et al. (2014). Preliminary results show (1) the developmental nature of disciplinary discernment from the HR-diagram by the participants and (2) the large discrepancy between disciplinary discernment by the astronomy educators and their students. We describe and discuss the qualitative nature of these differences and how this can have implications for teaching and learning astronomy.

This paper aim at investigating what astronomy students and experts discern from the multitude of different disciplinary affordances available in Hertzsprung-Russell (HR) diagrams. HR-diagrams are central to all of astronomy and astrophysics and used extensively in teaching. However, knowledge about what students and experts discern from these disciplinary representations are not well known at present. HR-diagrams include many disciplinary affordances that may be hidden to the novice student, hence we aim at investigating and describing what astronomy students at different university levels (introductory, undergraduate, graduate), and astronomy educators/professors, discern from such representation – referred to as disciplinary discernment. Data from a web based questionnaire were analysed using the Anatomy of Disciplinary Discernment (ADD) framework by Eriksson et al.(2014). Preliminary results show (1) the developmental nature of disciplinary discernment from the HR-diagram by the participants and (2) the large discrepancy between disciplinary discernment by the astronomy educators and their students. We describe and discuss the qualitative nature of these differences and implications for teaching and learning astronomy.

Differential cross sections for Compton scattering from the deuteron were measured at MAX-Lab for incident photon energies of 55 and 66 MeV at nominal laboratory angles of 45degrees, 125degrees, and 135degrees. Tagged photons were scattered from liquid deuterium and detected in three NaI spectrometers. By comparing the data with theoretical calculations in the framework of a one-boson-exchange potential model, the sum and the difference of the isospin-averaged nucleon polarizabilities, alpha(N) + beta(N) = 17.4 +/- 3.7 and alpha(N) - beta(N) = 6.4 +/- 2.4 (in units of 10(-4) fm(3)), have been determined. By combining the latter with the global-averaged value for alpha(p) - beta(p) and using the predictions of the Baldin sum rule for the sum of the nucleon polarizabilities, we have obtained values for the neutron electric and magnetic polarizabilities of alpha(n) = 8.8 +/- 2.4(total) +/- 3.0(model) and beta(n) = 6.5 -/+ 2.4(total) -/+ 3.0(model), respectively.

Students often find astronomy and astrophysics to be most interesting and exciting, but the Universe is difficult to access using only one's eyes or simple equipment available at different educational settings. To open up the Universe and enhance learning astronomy and astrophysics different planetarium software can be used. In this article we discuss the usefulness of such simulation software and give four examples of how such software can be used for teaching and learning astronomy and astrophysics.

We discuss different excitation processes behind the Fe II emission lines in the IUE spectrum of KQ Puppis (Boss 1985), a VV Cephei type of spectroscopic binary. Several pa pers have been published on the subject suggesting a number of processes behind the strong Fe II emission lines. We propose that there are two processes operating: selective photoexcitation by continuum radiation (PCR) from the B-star companion, and photoexcitation by accidental resonance (PAR) by the H Ly alpha radiation field. We suggest excitation channels for each of the Fe II emission lines identified in the spectrum.

The Fourier-transform spectrum from an iron-neon hollow-cathode lamp has been studied in the region 9000-11 000 Å. The 3d6(5D)5g subconfiguration of Fe II has been established by means of about 220 newly identified 4f-5g transitions. The 5g configuration is well represented by J K coupling, which is demonstrated by the application of the quadrupolic approximation. A consistent pattern in the FWHM for various types of Fe II transitions has been observed. Calculated oscillator strengths are given for all observed lines and their relative accuracy is estimated from observed intensities. The new data offer unprecedented tools for diagnostics of stellar atmospheres.

Various alternative models were used to describe the structure of 106Ru . For example, the General Collective Model (GCM) predicts shape-coexistence for 106Ru with a spherical and a triaxial minimum and strongly mixed structures, while in the IBA-2 calculations, where 106Ru was considered as transitional from vibrational U(5) to γ -soft O(6) , no need was found to include the shape-coexisting configurations. In order to provide additional constraints on the model interpretations, we have applied the Advanced Time-Delayed (ATD) βγγ(t) method to measure the level lifetimes of the excited levels in 106Ru . The new results include the half-lives of T 1/2 = 183(3) ps and 7.5(30)ps for the 2+ 1 and 2+ 2 states, respectively.